Liposomes have been widely used as an in vivo carrier of various therapeutic agents. Ideally, such liposomes should have a high encapsulating efficiency and an extended retention profile (i.e., minimal release of the drug before reaching the targeted site).
NanoVNB® is a liposomal vinorelbine product, which utilizes liposomes to enhance the retention of vinorelbine before it reaches the targeted site. A Phase I clinical trial of NanoVNB® showed enhanced anti-cancer efficacy, but the extended retention of vinorelbine in vivo also led to increased toxicity.
Therefore, there is a need to provide a liposomal composition that is useful for delivery of a therapeutic agent with an adjustable retention profile, and to obtain a balance between optimal anti-cancer efficacy and minimal side effects. The present invention addresses this need, as well as other important needs.